Card Folding

 The Problem:

 A friend has taken a particular shape of paper, and folded it exactly in half (both sides matching) – twice.

The final shape of the (four-thickness) paper is shown below:


Can you work out the original shape of the paper?

There may well be more than one possibility…


What if the final shapes were as shown here, instead? 

 Finally… can you find a nice, easy, polygonal final shape for which there is only one possible starting shape?!

Open the File as a Word Document


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Last modified: June 18, 2007